/Engine/Source/Runtime/SlateCore/Public/Application/SlateApplicationBase.h
Sets keyboard focus to the specified widget. The widget must be allowed to receive keyboard focus.
true if the widget is now focused, false otherwise.
bool SetKeyboardFocus ( const [FWidgetPath](API\Runtime\SlateCore\Layout\FWidgetPath) & InFocusPath, const EFocusCause InCause )